The COG SDC is responsible for all statistical and data operations within the COG. It also supports many of the administrative activities of the COG. The IT support required for all statistical and data center operations is also provided by the SDC grant. The specific aims of the SDC are to: 1. Collaborate on the development of the COG's scientific agenda, as full members of Disease and Modality Committees 2. Provide leadership in the design of COG research, collaborating on the development of study pre-concepts, concepts, and protocols and providing study statistical considerations, including sample size calculations and interim monitoring plans 3. Collaborate on the development of study case report forms used to collect the minimal data required for the evaluation of the study aims 4. Maintain a centralized remote data entry system to collect study data from COG institutions, resource centers, and reference laboratories, and maintain quality control procedures to assure the accuracy of COG research data 5. Monitor study data submitted by participating COG institutions, monitor the timeliness of data submission and provide institutions with expectancy and delinquency reports, review submitted data, coordinate the collection and review of materials collected for modality reviews (pathology, surgery, radiation therapy), and coordinate study committee review of study data 6. Monitor study conduct, including accrual, patient safety, and study outcome;prepare public protocol progress reports for the COG and confidential reports of interim outcome data for the COG's Data Monitoring Committees 7. Collaborate on the production of abstracts and manuscripts reporting the results of COG science 8. Conduct research on statistical methods that have direct relevance to COG's research goals and conduct special analyses (e.g., on prognostic factors, outcome for specific patient subsets, etc.), taking advantage of the wealth of information contained in the group's research databases 9. Provide statistical collaboration for the COG's correlative laboratory research agenda. 10. Collaborate with members of the Group Operations Center in the completion of various administrative activities, including institutional audits and institutional performance monitoring 11. Provide education and training to the Group membership, including collaboration on the training of new study chairs, collaboration on new and continuing education training for institutional clinical research associates and presentations on statistical issues of interest to the Group membership.